BSF TOWER HAMLETS BOW SCHOOL SPECIFICATION FOR EXTERNAL DRAINAGE FOR RFP

BSF TOWER HAMLETS
BOW SCHOOL
.
Head Office
Elizabeth House
House
39 York Road
LONDON SE1 7NQ
Tel: 020 7401 0020
TOWER HAMLETS BSF
TITLE
SPECIFICATION FOR EXTERNAL DRAINAGE
BOW SCHOOL
Name
Signature
Date
DESIGNED
LPH
21
DRAWN BY
JAP
06
CHECKED
SH
SH
APPROVED
DJC
DJC
DJC
12
1:1 @ A4
FOR RFP
SCALE & FORMAT
PROPOSED STATUS
JUNE 2012
BOW TER SPE 100004 EXTERNAL DRAINAGE
DATE OF 1ST ISSUE
FILE NAME
ALL
SL
R1
BOW
TER
SPE
100004
A
AREA
LEVEL
TRADE
School
ISSUER
TYPE
SEQUENCE NO.
REV.
NUMBER
TITLE
RELATED DOCUMENTS
A
REV
21/06/2012
Date
ALL REVISIONS
FOR RFP
Revision Title
Specification: BOW-TER-SPE-100004-EXTERNAL DRAINAGE
Table of Contents
Title
Page
Q10
Kerbs/edgings/channels/paving accessories
2
R12
Below ground drainage systems
3
TERRELL Arthurs Mission 30 Snowsfields London SE1 3SU
t: +44 20 7403 6111 [email protected] f: +44 20 7378 0378
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Member of TERRELL Group
Specification: BOW-TER-SPE-100004-EXTERNAL DRAINAGE
Q10
Kerbs/edgings/channels/paving accessories
TYPES OF KERBS/EDGINGS/CHANNELS
180
DRAINAGE CHANNEL SYSTEMS WITH GRATINGS
Manufacturer: ACO Technologies PLC or Similar Approved
Product reference: Multi Drain M100D
Sizes: M100D No 0.0 150mm depth
Constant depth units
Accessories – 605mm sump unit outlet (ACO Ref 23410) with roddable foul air trap and 100mm dia
outlet
Bedding: As shown on drawing no BOW-TER-DET-100001 External Drainage Details
Cover Gratings: Class A15 galvanised slotted steel grating or Brickslot grating in pedestrian areas or
Class D400 ducitle iron heelguard grating in areas with vehicle access.
Joints generally: Expansion joints may be necessary at intervals, with compressible filler and sealant
capping – check with the manufacturer. Otherwise, joints are not generally sealed
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Specification: BOW-TER-SPE-100004-EXTERNAL DRAINAGE
R12 Below ground drainage systems
GENERAL
100
EXISTING DRAINS
- Setting out: Before starting work, check invert levels and positions of existing
drains, sewers, inspections chambers and manholes against drawings. Report
discrepancies.
- Protection: Protect existing drains to be retained and maintain normal operation.
101
EXISTING SERVICES
- Check positions and levels of underground services before commencing
excavation. Hand dig carefully within 3m of any known or suspected service run.
- Notify service undertakers if service runs exposed by excavation or if drainage
work is to cross the line of a service. Follow service undertakers’ instructions
concerning work near service runs.
- Replace any service marker tapes or protective covers disturbed by drainage
work, in accordance with service undertakers’ instructions.
103
SEQUENCE OF WORK
Refer to drawings and BYUK program.
106
•
•
•
IN SITU CONCRETE FOR USE IN DRAINAGE BELOW GROUND
Standard: To BS 5328-1, -2, -3 and -4, or to BS 8500-1, -2 and BS EN 206-1.
Mix: to suit DS2 / AC2 ground conditions.
Equivalent or better mix: Submit proposals.
Different mixes may be used for different parts of the drainage work.
PRODUCTS
315
ONE PIECE GULLIES AND COVERS
- Standards:
- Clay: To BS EN 295-1 and Kitemark certified, or Agrément certified.
- Concrete: To BS 5911-6 and Kitemark certified, or Agrément certified.
- Plastics: To BS 4660 and Kitemark certified, or Agrément certified.
- Polypropylene: To BS EN 1852-1.
- Manufacturer:
Hepworth/Milton Precast or Similar Approved
- Sizes:
Road Gully - 450mm diameter, 1050mm deep
Yard Gully – 225mm diameter, 670mm deep
- Outlet sizes:
Road Gully – 150mm diameter
Yard Gully – 100mm diameter
- Covers:
- Product reference: Saint Gobain Pipelines or Similar Approved
- Material: Ductile Iron
- Loading grades to BS EN 124: A15 or D400 as specified on the drainage drawings
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Specification: BOW-TER-SPE-100004-EXTERNAL DRAINAGE
336
PIPES, BENDS AND JUNCTIONS – CLAY – FLEXIBLE JOINTS where drain diameters are between
100-450mm. Refer to Clause 346 for alternative specification.
- Pipes, bends and junctions: Vitrified clay to BS EN 295-1, with flexible joints,
Kitemark certified.
- Manufacturer:
Hepworth or Equivalent
- Product reference: Supersleve or Equivalent
- Strength:
Extra
- Sizes:
DN 100-450
- Jointing:
As detailed by manufacturer
- Bed class: Granular surround Type S or concrete surround Type Z. Refer to
Drainage drawings.
344A
PIPES, BENDS AND JUNCTIONS - PLASTICS - STRUCTURED WALL : [ for use where diamters
100-900mm. Refer to clause 336 & 346 for alternative specifications.]
Standard: To BS EN 13476-1 & 3, Kitemark certified.
- Manufacturer: Polypipe Civils or equivalent.
- Product reference: Ridgidrain/Ridgisewer or equivalent.
- Sizes: DN100 mm - 900mm
- Type of subsoil: various - see Soil Report.
- Bedding class: Granular Type S or concrete Type Z surround. Refer to Drainage Details drawing
346
PIPES, BENDS AND JUNCTIONS – PVC-U – SOLID WALL for use where diameter is 100mm 600mm.
Refer to Clause 336 for alternative specifications
Standard: To BS EN 1401-1, Kitemark certified.
Manufacturer: Hepworth or equivalent.
Product reference: Plastidrain/sewerdrain or equivalent.
Sizes: 100 mm – 600mm.
Type of subsoil: various - see Soil Report.
Bedding class: Granular Type S or concrete Type Z surround. Refer to Drainage drawings
•
•
•
371
401
RODDING EYES
- Standards:
- Plastics: To BS 4660 and Kitemark certified, or Agrément certified.
- Material:
Plastics
- Manufacturer:
Hepworth PlastiDrain or Similar Approved
- Product reference:
4A10SA Square Top Rodding Point
- Sizes:
110mm diameter
INSPECTION CHAMBERS - PLASTICS
- Standard: To BS 7158 or BS EN 13598-1, or Agrément certified.
- Diameter:
Nominal 450mm
- Manufacturer: Hepworth PlastiDrain or Similar Approved
- Bases: Product reference:
Hepworth SPIC6/2
- Access covers and frames: Loading grades to BS EN 124: A15
- External Covers – Circular Hepworth Ref SPK8
- Internal Covers – Airtight, screwed down covers, square recessed to take floor finishes –
Clarke-Drain ref CLKS 450SR/46SL (or similar approved).
- Covers shall be coordinated with the landscape design and recessed covers to
take paving shall be provided where indicated on the drainage plan
(Hepworth Ref SPCR8)
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Specification: BOW-TER-SPE-100004-EXTERNAL DRAINAGE
407A
MANHOLES AND INSPECTION CHAMBERS – CONCRETE:
Standards:
- To BS 5911-3 and BS EN 1917 and Kitemark certified; or
- To BS 5911-4 and BS EN 1917.
Manufacturer: [CPM Group Ltd or similar approved]
Shape: [Circular]
Sizes: [up to 2400mm diameter].
Cement type and content: [To BS 5911-1 and BS EN 1916].
Chamber sections:
- Jointing type: [as recommended by manufacturer].
Cover slabs:
- Product reference: [Heavy duty precast concrete].
- Thickness: [TBC].
- Loading grades to BS EN 124: [D400].
- Openings: To suit access covers.
Steps: [To clause 439].
433
•
•
•
435
CONVENTIONAL CHANNELS, BRANCHES AND BENCHING
Main channel: Bed solid in 1:3 cement:sand mortar.
Branches: Connect to channel, preferably at half pipe level, so that discharge flows
smoothly in direction of main flow.
Branches greater than nominal size 150 mm: Connect with the soffit level with that of
the main drain.
Connecting angle more than 45° to direction of flow: Use three-quarter section channel
bends.
Plastics channels: Use clips or ensure adequate mechanical key when bedding on to
mortar.
Benching: Form in concrete, to rise vertically from top of main channel to a level not lower
than soffit of outlet pipe, then slope upwards at 10% to walls.
Topping: granolithic concrete.
PREFORMED PLASTICS CHANNELS, BRANCHES AND BENCHING
Manufacturer:
to suit manholes
or equivalent.
Product reference:
to be approved
or equivalent.
Sizes and integral branches: To suit each manhole.
• Temporary caps: Remove as necessary.
• Bedding: 1:3 cement:sand mortar.
• Benching: Form in concrete, with 10% fall from manhole walls to component rim.
Topping: granolithic concrete
•
439
MANHOLE STEPS
- Standard: Stainless Steel or Polypropylene encapsulated ductile iron double step
rings 280mm min width at 250mm max centres.
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Specification: BOW-TER-SPE-100004-EXTERNAL DRAINAGE
464
STORMWATER HONEYCOMB UNITS
- Manufacturer: Wavin Plastics or similar approved (BBA Certificate no 03/4018)
- Product reference: Aquacell storage units
-Size: Overall size refer to Drainage Drawings (each individual unit 1m long x 0.5m wide x 0.4m
deep)
-The storage tank shall be vented to finished surface level by a 100mm diameter uPVC pipe finishing
in a suitable vent box at surface level eg. Hepworth Plastidrain Square Hopper with grid (ref
4H10A/4H11B) or similar approved.
471
ACCESS COVERS AND FRAMES
- Covers:
Grey iron or ductile iron to BS EN 124:
- Manufacture:
Saint Gobain Pipelines or Similar Approved
- Product reference:
600x600 manhole cover and frame. Cover embossed with SW or
FW as appropriate (SW = surface water, FW = foul water)
- Types:
Class A15, B125 or D400 as specified on drawings.
- Seating: Engineering bricks to BS 3921, Class B, laid in Class M1, M2 or Epoxy
mortar, or precast concrete cover frame units, Type 1 or Type 2 to suit cover shape.
- Bedding and haunching frame: Solidly in Class M1, M2 or Epoxy mortar over its
whole area, centrally over opening, top level and square with joints in surrounding
finishes. Cut back top of haunching to 30mm below top of surface material.
Covers shall be coordinated with the landscape design and recessed covers to
take block paving shall be provided where indicated on the drainage plan
472A
•
LIFTING KEYS
Submit: Suitable lifting keys for each type of access cover.
Timing: At completion.
EXECUTION
613
EXCAVATED MATERIAL
Turf, topsoil, hardcore, etc: Set aside for use in reinstatement.
623
•
625A
•
LOWER PART OF TRENCH - GENERAL
Trench from bottom up to 300 mm above crown of pipe: With vertical sides and of a width
as small as practicable but not less than external diameter of pipe plus 300 mm.
LOWER PART OF TRENCH - TRANSITION DEPTH
Depth of cover exceeding transition depth: Trench width up to 300 mm above crown of
pipe to be not more than:
Nominal pipe size DN
100
150
225
300
Transition depth (m)
6.0
5.4
4.0
2.9
Maximum trench width (mm)
600
700
800
900
The transition depth is the depth below which an increase in trench width may cause an
unacceptable increase in the load on the pipe. In most projects the pipe sizes and depths
will be such that this clause does not apply
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Specification: BOW-TER-SPE-100004-EXTERNAL DRAINAGE
626A
•
•
631
•
635
•
•
•
636A
•
637A
•
661A
LOWER PART OF TRENCH - GRANULAR BEDDING
Trenches with bedding class S (see clause 661A): Trench width to be not more than the
following, regardless of depth of cover:
Nominal pipe size (DN)
100 150
225
300
Maximum trench width (mm)
700 750
825
900
TYPE OF SUBSOIL
General: Where type of subsoil at level of crown of pipe differs from that stated for the type
of pipeline, obtain instructions before proceeding.
FORMATION FOR BEDDINGS
Timing: Excavate to formation immediately before laying beds or pipes.
Mud, rock projections, boulders and hard spots: Remove. Replace with consolidated
bedding material.
Local soft spots: Harden by tamping in bedding material.
Inspection of excavated formations: Give notice to Building Control.
COMBINED TRENCHES
Pipes at different levels in common trench:
Subtrench: Permissible provided soil of step is stable and unlikely to break away.
Subtrench not permissible: Relate trench depth to lower pipe. Increase thickness of
bedding to upper pipe as necessary.
Lower pipe: Backfill with compacted granular material to not less than half way up higher
pipe.
TRENCH SUPPORTS
Removal of trench supports and other obstacles: Sufficient to permit compacted filling of
all spaces.
CLASS S SUPPORT
- Granular material:
To BS EN 12620:2002/PD 6682-1:2003
- Pipe sizes DN 100 and DN 150:
Size 4/10.
- Pipe sizes DN 225 and DN 300:
Size 4/10 or 10/20.
- Bedding:
- Material: Granular, compacted over full width of trench.
- Thickness (minimum): 100 mm.
- Pipes: Dig slightly into bedding, rest uniformly on barrels and adjust to line and
gradient.
- Support:
- Material:
Granular.
- Depth:
To slightly above crown of pipe.
- Compaction:
By hand.
- Backfilling:
Material and depth: Protective cushion of selected fill to 300 mm above crown of
pipe; or additional granular material, to 100 mm above crown of pipe.
- Compaction:
By hand in 100 mm layers.
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Specification: BOW-TER-SPE-100004-EXTERNAL DRAINAGE
678
•
•
•
680
•
•
•
681A
•
•
683
•
•
•
•
CLASS Z SURROUND
Concrete blinding (over full width of trench): Allow to set before laying pipes.
Thickness: 25 mm.
Temporary pipe support: Folding wedges of compressible board. Prevent flotation.
Surround, to full width of trench:
Timing: After successful initial testing.
Depth: To 150 mm above crown of pipe or as shown on drawings.
Vertical construction joints: At face of flexible pipe joints using 18 mm thick compressible
board precut to profile of pipe. Socketed pipes: Fill gaps between spigots and sockets with
resilient material to prevent entry of concrete.
CONCRETE SURROUND FOR PIPE RUNS NEAR FOUNDATIONS
Concrete surround: Provide in locations where bottom of trench is lower than bottom of
foundation. Measurements are horizontal clear distances between nearest edges of
foundations and pipe trenches.
Trenches less than one metre from foundations: Top of concrete surround not lower than
bottom of foundation.
Trenches more than one metre from foundations: Top of concrete surround not lower than
D mm below bottom of foundation, where D mm is horizontal distance of trench from
foundation, less 150 mm.
CROSSOVERS
Concrete surround: Provide where two pipelines (other than plastics pipes) cross with less
than 300 mm separation.
Extent, on both pipes: 1 m centred on the crossing point, and beyond as necessary to come
within 150 mm of next nearest flexible joints.
LAYING PIPELINES
Pipes and fittings: From same manufacturer for each pipeline.
Jointing: Use recommended lubricants. Leave recommended gaps at ends of spigots to
allow for movement.
Jointing differing pipes and fittings: With adaptors recommended by pipe manufacturer.
Laying pipes: To true line and regular gradient on even bed for full length of barrel with
sockets (if any) facing up the gradient.
Protect from damage and ingress of debris. Seal all exposed ends during construction.
Timing: Minimize time between laying and testing. Backfill after successful initial testing.
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Specification: BOW-TER-SPE-100004-EXTERNAL DRAINAGE
689
•
•
691A
PIPELINES PASSING THROUGH STRUCTURES
Pipelines that must be cast in or fixed to structures (including manholes, catchpits and
inspection chambers): Provide short length (rocker) pipes near each external face, with
flexible joint at each end:
Pipe size (DN)
Distance to first joint
Short length
from structure (mm)
(mm)
100 & 150
150
600
225
225
600
Pipelines that need not be cast in or fixed to structures (e.g. walls to footings): Provide
either:
Short length (rocker) pipes as specified above, or
Openings in the structures to give 50 mm minimum clearance around the pipeline.
Closely fit a rigid sheet to each side of opening to prevent ingress of fill or vermin.
BENDS AT BASE OF SOIL STACKS ETC
- Type: Nominal 90° rest bends
- Radius to centreline of pipe (minimum) 200mm
- Bedding: Do not impair flexibility of pipe couplings.
- Material: Plastics/UPVC
695
•
715
•
•
720
•
721A
•
725A
•
BACKDROP PIPES OUTSIDE MANHOLE WALLS
General: Encase in concrete.
Thickness (minimum): 150 mm.
Excavation beneath backdrop pipe and its surround: Replace with concrete.
BACKFILLING TO PIPELINES
Refer to Drainage Details drawing.
Granular surround to be hand compacted to minimum 300mm above crown of pipe.
Maximum layer thickness 300mm.
BACKFILLING UNDER ROADS AND PAVINGS
Backfilling from top of surround or protective cushion up to formation level: Granular
Subbase Material Type 1 to HA Specification for Highway Works, Clause 803, laid and
compacted in 150 mm layers.
BACKFILLING OVER CONCRETE
Minimum times from placing concrete:
Backfilling generally: 24 hours.
Heavy compactors and traffic loads: 72 hours.
TEMPORARY BRIDGES
Trench bridges: As necessary to prevent construction traffic damaging pipes after
backfilling.
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Specification: BOW-TER-SPE-100004-EXTERNAL DRAINAGE
777A
•
•
•
TERMINAL/ACCESS FITTINGS
Setting out: Square with and tightly jointed to adjacent construction.
Bedding and surrounds: Concrete, 150 mm thick.
Permissible deviation in level of gully gratings: +0 to -10 mm.
Exposed openings in fittings: Fit purpose made temporary caps. Protect from site traffic.
•
CONNECTIONS TO SEWERS
General: Connect new pipework to existing adopted sewers to the requirements of the
Adopting Authority or its agent.
778A
COMPLETION
901
•
•
•
911
•
•
921
•
•
•
922A
REMOVAL OF DEBRIS AND CLEANING
Preparation: Before cleaning, final testing, CCTV inspection if specified and immediately
before handover, lift covers to manholes, inspection chambers and access points. Remove
wrappings, mortar droppings and any other debris.
Cleaning: Thoroughly flush with water to remove silt and check for blockages. Rod
pipelines between access points if there is any indication that they may be obstructed.
Washings and detritus: Do not discharge into sewers or watercourses.
Covers: Securely replace after cleaning and testing.
TESTING AND INSPECTION
Dates for inspection: Give notice.
Attendance: Provide water, assistance and apparatus as required.
Remedial work: Repair leaks.
FINAL TESTING OF PRIVATE GRAVITY DRAINS AND SEWERS UP TO DN 300
Air testing preparation and method: To BS 8301, clauses 25.6.3.1 and 25.6.3.2.
Initial testing: To ensure that pipelines are sound and properly installed, air test short
lengths to BS EN 1610, clauses 13.1 and 13.2 immediately after completion of bedding/
surround.
Final testing: For final checking and statutory authority approval, water test to BS EN
1610, clause 13.1 and 13.3 all lengths of pipeline from terminals and connections to
manholes/ chambers and between manholes/ chambers.
TESTING OF ADOPTABLE AND LARGE PRIVATE SEWERS
Standard (sewers up to and including size DN 750): To 'Sewers for Adoption', clauses
4.7.3 to 4.7.5.
• Timing:
Initially, before backfilling.
Repeat test after backfilling, also testing for infiltration to 'Sewers for adoption', clause
4.7.7.
•
941
•
•
WATER TESTING OF MANHOLES AND INSPECTION CHAMBERS
Timing: Before backfilling.
Standard:
Exfiltration: To BS EN 1610, clause 13.3.
Infiltration: No identifiable flow of water penetrating the chamber.
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Specification: BOW-TER-SPE-100004-EXTERNAL DRAINAGE
960A
•
•
•
•
CCTV INSPECTION OF PRIVATE PIPELINES
General: Carry out and record internal inspection of all new drainage with CCTV
equipment.
Equipment and personnel: Provide as necessary, including suitable covered
accommodation for viewing monitor screen, together with personnel experienced in
operation of the equipment and interpretation of the results.
Illumination: Of adequate intensity.
Recording: Provide continuous position recording, still photographs and stopping of the
camera at any point.
Submit copy of videotape recording.
Remedying of defects that are revealed: Obtain instructions.
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